【作者】 晁青；

【导师】 徐明良；

【作者基本信息】 扬州大学 ， 遗传学， 2006， 硕士

【摘要】 水稻籼粳亚种间具有很强的杂种优势,然而,由于杂种的半不育特性,限制了其优势的进一步利用。值得庆幸的是水稻育种家们发现有些水稻品种与籼稻或粳稻杂交育性均表现正常,这样的品种称为广亲和品种,这一发现为籼粳亚种间杂种优势的利用提供了可能。研究表明控制这一性状的广亲和基因S5n位于水稻第6号染色体上。本实验室先前的研究将S5n精细定位到分子标记J13和J17之间,物理距离为50 Kb。对此区间的序列进行预测,确定了两个广亲和候选基因,Asp和CG2,分别编码天冬氨酸蛋白酶和一个功能未知的蛋白。对每一个候选基因,我们都构建二类表达载体,即过量表达载体和功能互补测验载体,而后将这些表达载体通过农杆菌介导转入到不含有广亲和基因的受体材料中,检测后代小穗育性,确定广亲和基因。结果如下:1.直接以‘Balilla’ב南京11’的杂交种为受体获得6个转化系,在海南种植,并检查小穗育性。候选基因Asp的转基因植株与未转任何载体的组培材料相比,小穗育性无明显差异;转基因植株与转空白载体的阴性对照相比,小穗育性明显提高,差异达显著水平,但平均育性仍然很低。2.以二个粳稻品种,‘Balilla’和‘武香粳’,为受体获得转基因植株,将这些转基因材料与籼稻品种‘南京11’杂交,同时检测杂交后代的基因型和小穗育性。结果表明只有一株转基因‘武香粳’(转Asp过量表达载体)与‘南京11’的杂种后代中,携带候选基因的杂种比同背景的不带候选基因的杂种平均育性提高14.15%,达极显著水平,并且平均育性高于50%。初步结果推测编码天冬氨酸蛋白酶的基因Asp可能与水稻的广亲和特性有关,具体的机理有待进一步研究。更多还原

【Abstract】 Strong heterosis has been observed in rice inter-subspecific hybrids, however, such heterosis could not find its application in rice production due to an occurrence of semi-sterility spikelets. Fortunately, the rice breeders found some very unique varieties, called wide-compatibility varieties, that could lead to normal fertility in the hybrids when crossing to either indica or japonica rice subspecies. This discovery made it possible to utilize the strong heterosis of inter-subspecific hybrids. The S5n gene, located on chromosome 6, has previously been manifested to be responsible for the wide-compatibility in rice.In our previous report, the S5n gene has been mapped within a 50 kb interval delimited by the left marker J13 and the right marker J17. Sequence analysis of the 50 kb region revealed two candidate genes, coding an aspartyl protease and a hypothetical protein. In the present study, we constructed the two kinds of express vectors, over-expression vector and functional complementary test vector, for each candidate gene. All the express vectors were transformed into the rice receptors for determining the gene responsible for the wide-compatibility in rice.The results for transformation are summarized as follows:1. By using the‘Balilla×Nanjing11’F1 hybrid seeds as receptors, six transgenic lines were obtained and grew in Hainan winter nursery for investigating the spikelet fertilities. Comparing the transgenic lines with the candidate genes with those transformants carrying no vector, no any difference has been observed in the更多还原